1. Field of the Invention
The present invention relates to a recording apparatus used as an output device of an ink-jet recording apparatus exerting recordation by ejecting an ink from a recording unit to a recording medium, or an apparatus having such a function, e.g., a facsimile, a duplicator, a printer multifunction machine and a workstation.
2. Description of the Related Art
In recent years, color documents have been widely spread in office use, and various kinds of output apparatuses have been proposed therefor. In particular, an ink-jet system, which can be miniaturized with low cost, is used in various kinds of output apparatuses.
A recording head used in the ink-jet system is constituted with an energy generating unit, an energy converting unit for converting energy generated by the energy generating unit to an ink ejecting force, an ink ejecting outlet for ejecting an ink droplet with the ink ejecting force, and an ink feeding path connected to the ink ejecting outlet for feeding an ink Examples of the energy generating unit include devices using an electromechanical converting element, such as a piezoelectric element, and devices, in which an ink is heated with an electrothermal conversion element having a resistive heater element to form a bubble, and the ink droplet is ejected with the formation of the bubble.
In the recording head utilizing an electrothermal conversion element, not only ink ejecting outlets can be arranged at a high density owing to the small size of the electrothermal conversion element, but also a production technique of a semiconductor integrated circuit can be transferred for the production technique therefor. Accordingly, a recording head having a large number of ink ejecting outlets with high accuracy can be miniaturized and can be produced at low cost.
However, what has been commonly used is a printing system referred to as a serial scanning system, in which a recording head is reciprocally moved with recording paper being conveyed to print by one line. While the system is of a small size and low cost, it has such a problem in that the printing speed is low due to necessity of plural frequencies of scanning of the recording head for forming an image over the paper. It is necessary to lower the scanning frequency in order to improve the printing speed, and extension of a recording head is essential therefor. At the outrance of the extension of a recording head, such a non-scanning printing system is proposed in that a recording head having the same width as recording paper is used. The printing system uses an ink-jet recording apparatus having a recording head having a width equivalent to recording paper, within which a large number of ejecting outlets are arranged over the length, which is substantially the same as the recording paper, and recordation is effected by moving the recoding paper with respect to the fixed recording head.
As described in the foregoing, in order to improve the printing speed to apply to office use, such an ink-jet recording apparatus is proposed that effects printing with a non-scanning recording head corresponding to the paper width on recording paper being continuously conveyed.
In order to maintain good ink ejection performance of an ink-jet recording apparatus, such operations are necessarily carried out with a maintenance device as ejection of an ink droplet in a non-printing state (dummy jet), cleaning of a nozzle surface (wiping), and prevention of an ink from being dried (capping).
For example, in the case where the non-printing state is continued for a prolonged period of time, the ink is dried to clog the nozzle, and dusts are attached to the nozzle surface. As a result, an ink droplet cannot be ejected (dot dropout), or the ejection direction of an ink droplet is changed to lower the printing quality or to disable printing.
Accordingly, in the case where printing is paused for a prescribed period, the recording head is moved from the printing position to a maintenance position within the ink-jet recording apparatus, and dusts attached to the nozzle surface of the recording head are wiped to refresh the nozzle surface.
In order to prevent the ejection performance of an ink droplet from being changed due to change in viscosity of the ink and formation of a bubble, an ink droplet is ejected from the recording head to a receiving member in a non-printing state.
In order to prevent the nozzle surface (nozzle) of the recording head from being dried, furthermore, a cap member is provided. The cap member presses a rubber part onto the nozzle surface to seal the nozzle surface (nozzle) from the exterior.
The ink-jet recording apparatus thus configured as described in the foregoing terminates printing operation after completing printing of a prescribed number of sheets and then effects maintenance operation. Therefore, the productivity is lowered in continuous printing.
In order to solve the problem, proposals have been made, in which a receiving member for receiving dummy jet is disposed at a position opposite to a nozzle surface of a recording head (as described, for example, in JP-A-11-348313 and JP-A-12-15835). In the ink-jet recording apparatus described in JP-A-11-348313 and JP-A-12-15835, a belt for conveying recording paper passes on the downside of the receiving member, whereby the receiving member is disposed at the position opposite to the recording head (nozzle surface). According to the configuration, dummy jet can be ejected onto the receiving member within a period between passage of preceding recording paper and arrival of subsequent recording paper, whereby the productivity is improved.
It has been also proposed that a hole for dummy jet is provided in a belt for conveying to enable ejection of dummy jet during continuous printing, whereby the productivity is improved (as described in JP-A-13-113690).
However, in the techniques described in JP-A-11-348313 and JP-A-12-15835, the recording head is moved from the printing position to the maintenance position upon carrying out the maintenance operation other than dummy jet. In the case where the apparatus is configured to move the recording head between the maintenance position and the printing position, such a problem occurs in that misalignment of the recording head occurs at the, printing position due to the movement to fluctuate the printing quality. Furthermore, another problem occurs in that the constitution of the apparatus is complicated due to the movement of the recording head within the apparatus.
In the case where recording paper is conveyed with a belt having a hole as described in JP-A-13-113690, on the other hand, printed matters can be output without problem in operation for a short period, but there are cases where stress is concentrated to the edge of the hole on the belt in operation for a prolonged period to impair stable running of the belt, whereby printing quality is deteriorated.